Init of static member object

[mpaw]

Hi.

I have class in which I have static member, which is RenderWindow object. How can I initialize it?

class A
{
  public:
  static sf::RenderWindow window;
};

How Can I init it in my program?
Thanks

[Athenian Hoplite]

Like all other static objects. In your cpp file I'd imagine. 

// Header file
class A
{
  public:
  static sf::RenderWindow window;
};

// Cpp file
sf::RenderWindow A::window;
 

You can use the default constructor and then at runtime use the sf::RenderWindow::create method to (re) create the window with the parameters you somehow got programmatically or replace "= sf::RenderWindow();" with the usual constructor and pass the arguments you want hardcoded.

[mpaw]

I tried, but there is no static constructor defined for RenderWindow

[Athenian Hoplite]

What I told you before works. sf::RenderWindow defines more than one constructor which can be used to instantiate static variables the way I described. You can also derive a class from sf::RenderWindow if you prefer but that is beside the point.

Note: C++ doesn't have "static constructors" like in C#.

This works:

class A
{
  public:
  static sf::RenderWindow window;
};

sf::RenderWindow A::window;
 

[mpaw]

I get error:

... error: use of deleted function 'sf::RenderWindow::RenderWindow(const sf::RenderWindow&)'|
... note: 'sf::RenderWindow::RenderWindow(const sf::RenderWindow&)' is implicitly deleted because the default definition would be ill-formed:|

[Athenian Hoplite]

What code is producing that error ? I have compiled the code with no errors so this is not what is giving you that.

[Laurent]

Just

sf::RenderWindow A::window;

No need to copy-construct from a default-constructed instance

[Athenian Hoplite]

Just

sf::RenderWindow A::window;

No need to copy-construct from a default-constructed instance

whoops-a-daisy
edited

[eXpl0it3r]

Beyond that, you should not use static variables for SFML resources, as the initialization and destruction order of static/global variables is undefined and can lead to crashes.